The invention relates generally to an apparatus and method for forming pleats or ruffles in a sheet-like material, in particular a thermoplastic material. The invention also relates to a laminated sheet-like article having pleats or ruffles formed therein.
In a variety of sheet-like products such as decorations, curtains, wall or floor coverings, and table skirting material, pleats or ruffles may be desired on the entire surface or adjacent one edge of the material. In the manufacture of such articles, it is desirable to produce the pleats or ruffles in a quick and reliable manner. For purposes of the description which follows, the terms "pleat" and "ruffle" shall be regarded as equivalent.
A variety of methods have been employed to form pleats in a sheet-like material. Typically, the methods involve the use of a sewing machine that gathers the material to form pleats and needle stitches the pleats to hold them in place. Typically, an oscillating ruffling blade is used to gather the material into ruffles. Another device known for forming pleats in sheet-like material is disclosed in U.S. Pat. No. 2,632,495 to Agee. In that device, a single layer of material is passed between three co-acting rollers, two of the rollers rotating at a rate greater than that of the third roller. The material is urged by the first two rollers toward the slower rotating roller, causing the material to double over itself forming pleats. These pleats are then held together by tape.
A disadvantage of the conventional methods of pleating is a general lack of uniformity in the spacing and size of the resulting pleats due to the manner in which the pleats are gathered and formed. For example, the ruffling blades of the conventional sewing machines typically do not gather an equal amount of material per pleat so that the size of the resulting pleats is inconsistent. Due to this inconsistent gathering and to a general lack of control over the precise timing of the oscillation of the blades, the spacing of the pleats is typically not uniform.